Type III Supracondylar Fracture, with posteromedial displacement.

Supracondylar Fracture

• The most common paediatric elbow fracture.
• Typically occurs in kids < 8 years of age.
  • This is a result of the ligament/joint capsule tensile strength being greater than that of the bone itself.
• Extension vs Flexion:
  • Extension:
    • >95% of all supracondylar fractures are extension related.
    • Olecranon forcefully driven into olecranon fossa.
    • Results in failure of anterior cortex & displacement of distal fragment posteriorly.
    • Can be further defined by the Gartland Classification.
  • Flexion:
    • Energy transferred from posterior aspect of proximal ulna to distal humerus.
    • Anterior displacement of the distal fragment and failure of cortex posteriorly.

The Gartland Classification.

• Type 1: Non-displaced.
• Type 2: Displaced fracture with intact posterior cortex.
• Type 3: Displaced fracture with no cortical contact.
  • A: Posteromedial rotation of the distal fragment.
  • B: Posterolateral rotation of the distal fragment.

Firstly, we should recall the ossification centres of the elbow & the helpful mneumonic “CRITOE”.

taken from *http://www.wikem.org/wiki/Elbow_X-ray_(Peds)

The Anterior Humeral Line.

• On a normal lateral elbow x-ray, a line drawn along the anterior surface of the humerus should pass through the middle third of the capitellum.
• If the capitellum falls posteriorly to this line, an extension-type supracondylar fracture is likely…

taken from *http://www.radiologytutorials.com

An abnormal anterior humeral line – taken from *http://www.radiologyassistant.nl/en/p4214416a75d87

The Radiocapitellar Line.

• A line drawn along the radial neck should intersect the capitellum.
• Failure to do so, suggests a radial head dislocation.
• For great examples see RadiologySigns – Three children with elbow pain… or Radial Head Dislocation @ Youtube.com

Fat Pads.

• An anterior fat pad protrudes from the Coronoid fossa.
  • It is normal unless bulging or shaped ‘like a sail’.
• A posterior fat pad is always pathological.

Adapted from wikimedia.org

Baumann’s Angle.

• An additional aid for diagnosing subtle supracondylar fractures.
• Angle is formed by a line drawn along the growth plate of the capitellum that transects a line running along the axis of the humerus.
• It should be ~ 75 degrees.

Left is normal. Right is obviously not...

Neurovascular compromise occurs in up to 49% of all Type III injuries.

• Median nerve:
  • Involved in 50% of cases.
  • Associated with posterolateral displacement.
• Radial nerve:
  • Involved in 1/3 of cases.
  • Associated with posteromedial displacement.
• Brachial artery:
  • Includes entrapment, laceration, intimal tear or compression (compartment syndrome).
  • Approximately 40% of cases.
  • Found in either medial or lateral displacement.

Be on the lookout for Compartment Syndrome.

• Pain on flexion or extension of fingers
• Forearm tenderness on palpation.
• Disproportionate pain to injury.
• Important as unrecognised ischaemic injury can result in Volkmann’s Ischaemic Contracture.

• Obviously, a limb with neurovascular compromise mandates immediate reduction.
  • Delay to the operating theatres may require a reduction attempt in the ED. Rosen’s demonstrates this manoeuvre quite well.
• Type I injuries;
  • Splint in ED (aim for 90 degrees of elbow flexion, with neutral rotation).
  • Outpatient referral to Orthopaedics is appropriate.
• Type II injuries;
  • No current consensus with regards to surgical management.
  • Closed reduction & plaster vs ORIF.
  • Referral to Orthopaedics at let them decide.
• Type III injuries.
  • Urgent Orthopaedic consultation –> OT for closed reduction, pinning or ORIF.
  • Splinting for comfort.
  • Thorough and repeated neurovascular examination.

1. Rosenʼs Emergency Medicine. Concepts and Clinical Approach. 7th Edition
2. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 7th Edition.
3. The Royal Children’s Hospital Melbourne; Clinical Practice Guideline on Supracondylar Fractures.